Memcached crash status 255 memcachetest windows

Created an attachment (id=557)
diag of node A

Install ns server 1.6.0beta3.1-4 32bit on 2 windows 7 64bit standalone machine.
Go through initial setup and set default bucket size to 1 GB.
Add node to create a cluster of 2 nodes. Rebalacne is ok.
Run memcachetest againsts default bucket.
./memcachetest -h 10.2.1.56:11211 -i 50000 -c 100000 -t 4
After a while, web console reloads and shows error.

Port server vbucketmigrator exited with status 3. Restarting
Port server memcached exited with status 255. Restarting.

http://screencast.com/t/NmQzZTBlZGEt